1. Field of the Invention
The present invention relates to a device for detecting the improper adjustment of a ventilatory support machine used on a mammal.
2. Description of the Related Art
Some people suffer from acute respiratory failure resulting, for example, from pneumonia, pulmonary edema or a secondary infection of chronic respiratory diseases. Mechanical ventilatory support may be required. Ventilatory support machines or ventilators comprise means for detecting the patient's inspiration and means for helping the patient to inspire by increasing the airflow or the pressure of the air inhaled by the patient.
Support thus consists in providing a predetermined volume of gas or pressurizing the airways. In both cases, different settings make it possible to adapt the flow of gas to the needs of the patient. The support machine must therefore be adapted to the respiratory behavior of the patient so as to obtain a “harmonious” relationship therebetween, that is to say that the patient has a satisfactory level of physical comfort and does not encounter any respiratory discomfort when using the support machine. If the settings are inappropriate, for example the airflow is too strong or, conversely, too weak, the patient may be uncomfortable or may even become distressed when breathing.
Various means have been used to detect disharmony of this type between the patient and the machine. In particular, it is known to simply ask the patient. However, this is not possible when the patient is asleep or in a coma.
It is also known to monitor ventilatory activity, in particular the frequency and use of the various respiratory muscle groups.
It is also possible to monitor the coordination between respiratory movements and the response of the ventilator in order to detect any asynchronicity or any ineffective actuation of the ventilator.
Lastly, it is known to measure indirect physiological elements which are used to measure ventilatory activity and, if necessary, to detect any desynchronized behavior of the ventilator. Said indirect physiological elements are, for example, occlusion pressure, morphology of the airway pressure curves and ventilatory work.
In practice, these elements must be used sensitively and all constitute indirect indicators of the sensations which the patient may be experiencing.